Mirrored UV's issue

Torch

Hey all, just wanted to ask people their opinion on when its suitable to use mirrored UVs for objects?

I’m just working on a piece of wall for a prop and thought about using mirrored UVs (both sides of the wall are mirrored on each other), but was concerned about too much repetition in the texture. I thought about just using a single plane with alpha for grunge to break up the repetition but wasn’t sure if this was a good way to do things?

I’ll try post an image of the prop and UV sheet when I get back. Any advice would be appreciated, thanks!

Spudnik

I'd think that if they are on opposite sides of the wall (i.e. can never be see at the same time) you should be okay.

warinmysky

I suppose if it were me, I'm always a fan of using mirrored UV's when possible. I would keep the repeating textures on walls for example and break them up using decals in UDK (akin to your alpha plane for grunge). Just my two cents

McGreed

I often (since I saw it in UDK) blend textures in the shader using vertex paint, and avoiding too much repeating texture as well. Find that it works better then decals and gives more freedom and easier to adjust.

Macattackk

i wouldnt use mirroring on a wall. youll be able to see the mirror point and itll look weird most likely. just use tiling texture and do what McGeed said.

GeeDave

I would personally avoid going the route of alpha planes to add grunge and the like, for one it's a bit of a clunky workflow in terms of making easy changes, secondly you've got the issue of either likely clipping, or obviously floating geo (view angle dependent), thirdly you may run into trouble with alpha sorting if you wanted to layer up any more decals over each other, and fourthly... tying onto the previous point, you'd be creating unnecessary overdraw in a game environment.

Are you using a game engine? Or is this all to be done inside a 3d package?

Lastly, I hate to be "that guy" but:

I’ll try post an image of the prop and UV sheet when I get back.

Why not just post the image when making the thread? It would get you a lot more replies as it's hard to visualise where and what you're mirroring, or if you could just overlay UV's instead of flipping them. I would imagine Spudnik is probably on the money, but it never hurts to be concise.

Torch

Hey all, thanks for the awesome replies! I actually posted the thread at work, and was hoping to get some replies before getting back so I could hit the ground running.

Here's a couple of pics of what I was speaking about, first the WIP scene:



....and the UV layout with mirrored UVs for the wall:



Was hoping to use Marmoset or UDK for previewing

Kurt Russell Fan Club

If you're only using that brick texture once in your game, that seems fine. The mirror axis for the bricks does show a little seam, so you could move your UVs in a touch from the island edge to fix it.

If you're using other assets that have the same bricks, you probably want to either move it to the corner and make it a tile-able section -- or separate the bricks out into a separate, generic tiling texture.